Blue-printing machine.



UNITED sfrarns IATENT oFrIoE.

WILLIAM O. W AKEFIELD, OF SCHENCTADY, NEV YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NE YORK.

BLUE-PRINTING. MACHINE. i

Specification of Letters Pateif..

Patented Aug. 15, 1905.

Application filed February 24.1904. Serial No. 195,007.

To all whom, t mail concern" Be it known that l, WILLIAM O. WAKEFIELD, a citizen of the United States, -residing at Schenectady` county of Schenectady, State of New York, have invented certain new and useful Improvements in Blue-Printing Machines, of, which the following is a specification.

The present invention relates to blue-printing machines, and more especially to that class of such machines in which the actinic rays are produced by artificial means.

The object of my invention is to provide means for supporting and operating the binding sheet or apron of blue-printing machines which shall be more certain of operation than the devices heretofore in use for this purpose; and a further object of my invention is to provide such an arrangement of the binding sheet or apron with respect to the source of light and the sensitized surface that it will automatically move into such position that it will screen the sensitized surface from the light-rays when the drawings or tracings and the sensitized surfaces are being' adjusted to position or removed therefrom.

For an understanding of my 4invention reference may be had to the accompanying drawing, forming a part of this specification, which shows my invention applied to a blue-printing machine of the same general construction as that shown in the Patent No. 712,076, granted October 28, 1902, to S. L. G. Knox and myself.

The machine consists of two end frames having braced legs A and pairs of oppositelydisposed semicircular heads B, and between these end frames cylindrical glass platesO are supported by means of suitable shoulders I) near the peripheries of the heads B. The light-rays are emitted from electric lamps E, suspended near the axes of the glass plates C from a bar extending over the machine and supported by brackets F at the tops of the end frames. The top edges of the glass plates C are somewhat removed from the lamps E and are supported by transverse bars 1, extending from end frame to end frame. .Other transverse bars 2 are similarly arranged in proximity to the lamps, and parallel thereto are rollers 3, journaled in the end frames. To each pair of bars 1 2 are'secured the opposite ends of a binding sheet or apron 4, which is of a width to extend across the space between the end frames with clearance and of a length slightly more than twice the peripheral width of the glass plate C. The arrangement of the sheet or apron 4 with relation to the roller 3 and the bars 1 and 2 is such that when in retracted positiomas indicated at the right of the drawing, it falls in a long fold between the roller 3 and bar 2 down past the lamps E, thereby eifectually interposing a double thickness of material between the lamps and the printing-surface.

In order to weight the sheet or apron between bar 2 and roller 3, I place a heavy rod or roll 5 in the bight of the sheet.

The means for drawing each sheet down over the glass plate C and the sensitized paper placed thereon consists of a roller 6, which takes in a bight in the front end of the sheet, so that as the roller is forced downward the sheet passes over the upper side thereof and is distributed over the glass plate and printing materials carried thereon at the under side thereof. The roller is journaled in the free ends of arms 7, pivoted to the end framesvat the axes of the cylindrical glass plates C, and these arms are provided with sprocket-wheels 8, over which flexible connections 9 toa treadle l0 pass, so that when the treadle is pressed upon both arms are moved simultaneously, carrying the roller parallel to its original position and the sheet or apron is evenly distributed over the glass plate. The rear ends of the flexible connections 9 are connected to retractile springs Il, so that when the treadle is released from the catch l2 the arms 7 are returned to the elevated position by the recoil of the springs.

It is apparent that my invention is applicable to blue-printing machines generally, and I accordingly do not desire to restrict myself to the particular embodiment herein described and illustrated.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

l. In a blueprinting machine having a transparent support for the printing materials, the combination of a binding sheet or apron having one end held in fixed relation with said transparent support, and a roller arranged in a fold of said sheet or apron but unattached thereto and movable over the transparent support.

2. In a blue-printing machine having a transparent support for the printing materials,

the combination of a binding sheet or apron having one end held in fixed relation with said transparent support, a roller arranged in a fold of said sheet or apron, but unattached thereto and means for moving said roller over said support and maintaining it parallel to its original position.

3. In a blue -printing machine having a transparent support for the printing materials, the combination ot' a binding sheet or apron, means for distributing it over the transparent support, and means for guiding the sheet or apron between the source ot' light and transparent support when retracted.

4. In a blue printing machine having' a transparent support for the printing materials, the combination otl a iexible binding sheet or apron having one end attached to a liXed part, and guides whereby the sheet or apron is caused to fall in a fold between the source ot' light and the transparent support when retrae-ted.

5. In a blue -printing machine having a transparent support forthe printing materials, the combination ot' a iexible binding sheet or apron having one end attached to a fixed part, and a guide-roller journaled parallel to said fixed part and adapted to guide said sheet or apron into a fold between the source of light and the transparent support when retracted.

6. In a blue -printing machine having a transparent support for the printing materials, the combination ot a stationary bar and a roller mounted parallel to one edge of said support,

a flexible binding sheet or apron secured to said stationary7 bar and passing over said roller, and a revolving' weight carried in the bight of said sheet or apron between the roller and bar.

7. In a blue printing machine having a transparent supportfor the printingmaterials, the combination of two horizontal stationary supports, a iexible sheet or apron secured at its ends to said stationary supports and adapted to fall in a fold between them when retracted, and a roller movable over said transparent support and arranged in a bight ol the sheet or apron so that the latteris distributed over the transparent support when said rollerl is moved in one direction and removed therefrom when said roller is moved in the opposite direction.

8. In a blue -printing machine having a cylindrical transparent support 'for the printing materials, the combination of two stationary supports and a roller mounted on said machine parallel to the axis of said cylindrical support, a iiexible sheet or apron secured at its ends to said stationary supports and passing over said roller.v and a second roller carried by arms pivoted about the axis oi said cylindrical support and arranged in a bight in said sheet or apron.

In witness whereof I have hereunto set my hand this 23d day of February, 1904.

TILL/IAM O. VVAKEFIELD.

VVit-nesses:

BENJAMIN B. HULL, HELEN ORFoRD. 

